Author's

PHP DEVELOPER

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Rasmus Lerdorf, who wrote the original Common  Gateway Interface (CGI) component together with Andi Gutmans and Zeev Suraski, who rewrote the parser that formed PHP 3

PHP is an open source general-purpose server-si
de scripting language originally designed for Web development to produce dynamic Web pages. It is one of the first developed server-side scripting languages to be embedded into an HTML source document rather than calling an external file to process data. The code is interpreted by a Web server with a PHP processor module which generates the resulting Web page. It also has evolved to include a command-line interface capability and can be used in standalone graphical applications. PHP can be deployed on most Web servers and also as a standalone shell on almost every operating system and platform, free of charge. A competitor to Microsoft's Active Server Pages (ASP) server-side script engine and similar languages, PHP is installed on more than 20 million Web sites and 1 million Web servers. Software that uses PHP includes Drupal, Joomla, MediaWiki, and WordPress.

PHP was originally created by Rasmus Lerdorf in 1995. The main implementation of PHP is now produced by The PHP Group and serves as the formal reference to the PHP language. PHP is free software released under the PHP License, which is incompatible with the GNU General Public License (GPL) due to restrictions on the usage of the term PHP.

PHP development began in 1994 when the programmer Rasmus Lerdorf initially created a set of Perl scripts he called "Personal Home Page Tools" to maintain his personal homepage. The scripts performed tasks such as displaying his résumé and recording his web-page traffic. Lerdorf initially announced the release of PHP on the comp.infosystems.www.authoring.cgi Usenet discussion group on June 8, 1995.He rewrote these scripts as Common Gateway Interface (CGI) binaries in C, extending them to add the ability to work with Web forms and to communicate with databases and called this implementation "Personal Home Page/Forms Interpreter" or PHP/FI. PHP/FI could be used to build simple, dynamic Web applications. Lerdorf released PHP/FI as "Personal Home Page Tools (PHP Tools) version 1.0" publicly on June 8, 1995, to accelerate bug location and improve the code. This release already had the basic functionality that PHP has today. This included Perl-like variables, form handling, and the ability to embed HTML. The syntax was similar to Perl but was more limited and simpler, although less consistent. A development team began to form and, after months of work and beta testing, officially released PHP/FI 2 in November 1997.

Zeev Suraski and Andi Gutmans rewrote the parser in 1997 and formed the base of PHP 3, changing the language's name to the recursive initialism PHP: Hypertext Preprocessor. Afterward, public testing of PHP 3 began, and the official launch came in June 1998. Suraski and Gutmans then started a new rewrite of PHP's core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan, Israel.

On May 22, 2000, PHP 4, powered by the Zend Engine 1.0, was released. As of August 2008 this branch is up to version 4.4.9. PHP 4 is no longer under development nor will any security updates be released.

On July 13, 2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5 included new features such as improved support for object-oriented programming, the PHP Data Objects (PDO) extension (which defines a lightweight and consistent interface for accessing databases), and numerous performance enhancements. In 2008 PHP 5 became the only stable version under development. Late static binding had been missing from PHP and was added in version 5.3.

A new major version has been under development alongside PHP 5 for several years. This version was originally planned to be released as PHP 6 as a result of its significant changes, which included plans for full Unicode support. However, Unicode support took developers much longer to implement than originally thought, and the decision was made in March 2010 to move the project to a branch, with features still under development moved to trunk.

Changes in the new code include the removal of register_globals, magic quotes, and safe mode. The reason for the removals was that register_globals had opened security holes by intentionally allowing runtime data injection, and the use of magic quotes had an unpredictable nature. Instead, to escape characters, magic quotes may be replaced with the addslashes() function, or more appropriately an escape mechanism specific to the database vendor itself like mysql_real_escape_string() for MySQL. Functions that will be removed in future versions and have been deprecated in PHP 5.3 will produce a warning if used.

Many high-profile open-source projects ceased to support PHP 4 in new code as of February 5, 2008, because of the GoPHP5 initiative, provided by a consortium of PHP developers promoting the transition from PHP 4 to PHP 5.

Since version 5.4, PHP has native support for Unicode or multibyte strings, allowing strings as well as class-, method-, and function-names to contain non-ASCII characters.

PHP interpreters are available on both 32-bit and 64-bit operating systems, but on Microsoft Windows the only official distribution is a 32-bit implementation, requiring Windows 32-bit compatibility mode while using Internet Information Services (IIS) on a 64-bit Windows platform. Experimental 64-bit versions of PHP 5.3.0 were briefly available for MS Windows, but have since been removed.

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 J-QUERY DEVELOPER's

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Corey Frang (Chicago, United States)

Infrastructure Lead
Corey is an active contributor to most of the jQuery teams and is active in jQuery community on IRC, and Stack Overflow. He restructured the effects modules in both UI and Core, maintains the jQuery Color Animations plugin, and puppeteers the new jQuery servers. He hopes that his work will “effect” your websites positively.

Scott González (North Carolina, United States)

jQuery UI Project Lead
Secretary
Scott is a web developer living in Raleigh, NC. As the jQuery UI Project Lead, he puts a lot of effort into maintaining the existing code base to make sure it is small, efficient and consistent. Scott also leads the accessibility team and works with new contributors to help improve the project and the community.

Dan Heberden (Oregon, United States)

Technology Lead
Dave Methvin (United States)

jQuery Core Lead
President
Dave is a long-time contributor to jQuery, providing extensive help on the jQuery bug tracker and in the jQuery discussion forums. As the lead of the jQuery dev team he works to ensure high quality, timely, releases of the library, organizes the planning and development efforts of the team, and generally drives the direction of the library.

Todd Parker (Boston, United States)

Dave Methvin (United States) jQuery Core Lead
President
Dave is a long-time contributor to jQuery, providing extensive help on the jQuery bug tracker and in the jQuery discussion forums. As the lead of the jQuery dev team he works to ensure high quality, timely, releases of the library, organizes the planning and development efforts of the team, and generally drives the direction of the library.

Todd Parker (Boston, United States)

jQuery Mobile Lead
Todd, a principal at Filament Group Inc., is a jQuery board member and project and design lead for the jQuery Mobile team. He is involved with the design of the ThemeRoller application and CSS class frameworks. Todd is co-author of the Peachpit book “Designing With Progressive Enhancement”, contributor to the O’Reilly “jQuery Cookbook” and frequent presenter on the topics of mobile, progressive enhancement, accessibility, and responsive web design.

John Resig (Boston, United States)

John was the original creator of the jQuery library. He works with the jQuery dev team and the jQuery board to help set the direction of the project

Leah Silber (California, United States)

Events Lead
Community and Marketing Committee Chair

Leah is responsible for jQuery fundraising and event management, as well as for online marketing and sponsorship initiatives, like the 14 Days of jQuery. She co-founded Tilde, an open source startup in San Francisco. She previously worked as a consultant for clients in the tech sector, and was employed managing the Community Marketing and Events department at Engine Yard. She runs GoGaRuCo, the annual San Francisco Ruby Conference, and in 2010, started and ran the Ruby Summer of Code program. She is originally from Brooklyn, NY and now lives in San Francisco, CA with her husband.

Adam Sontag (New York, United States)

Director of Developer Relations and Marketing

Adam J. Sontag is a New York City-based developer with Boston’s Bocoup. He’s the Developer Relations lead for jQuery and jQuery UI and co-host of the yayQuery podcast. In other words, he’s dedicated to keeping the jQuery project in sync with the community’s needs and wants.

Rick Waldron (Boston, United States)

Rick Waldron works at Bocoup in Boston, where he is a JavaScript enthusiast and evangelist and jQuery core committer.

Ralph Whitbeck (New York, United States)

Ralph is a Senior Developer at appendTo, LLC where he works with an awesome team of designers and developers delivering Front-end code for clients. Example projects include responsive web, widget development, product development, HTML5/CSS3, and much more. Ralph has been a member of the board since October 2009.

Richard D. Worth (Washington, D.C., United States)

Executive Director

Richard D. Worth is Executive Director of the jQuery Foundation. He lives in the Washington, D.C. area and works for Bocoup, training mobile and web developers in JavaScript, jQuery, and jQuery UI.

Jörn Zaefferer (Cologne, Germany)

Testing Lead
jQuery UI Development Lead

Jörn is a freelance web developer, consultant and trainer, based in Cologne, Germany.

Jörn evolved jQuery’s testsuite into QUnit, a JavaScript unit testing framework, and maintains it. He created and maintains a number of popular plugins.

As a jQuery UI development lead, he focuses on the development of new plugins, widgets and utilities.

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CSS DEVELOPER

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Style sheets have existed in one form or another since the beginnings of SGML in the 1980s. Cascading Style Sheets were developed as a means for creating a consistent approach to providing style information for web documents.As HTML grew, it came to encompass a wider variety of stylistic capabilities to meet the demands of web developers. This evolution gave the designer more control over site appearance, at the cost of more complex HTML. Variations in web browser implementations, such as ViolaWWW and WorldWideWeb, made consistent site appearance difficult, and users had less control over how web content was displayed. Robert Cailliau wanted to separate the structure from the presentation. The ideal way would be to give the user different options and transferring three different kinds of style sheets: one for printing, one for the presentation on the screen and one for the editor feature.

To improve web presentation capabilities, nine different style sheet languages were proposed to the World Wide Web Consortium's (W3C) www-style mailing list. Of the nine proposals, two were chosen as the foundation for what became CSS: Cascading HTML Style Sheets (CHSS) and Stream-based Style Sheet Proposal (SSP). CHSS, a language that has some resemblance to today's CSS, was proposed by Håkon Wium Lie in October 1994. Bert Bos was working on a browser called Argo, which used its own style sheet language called SSP. Lie and Yves Lafon joined Dave Raggett to expand the Arena browser for supporting CSS as a testbed application for the W3C. Lie and Bos worked together to develop the CSS standard (the 'H' was removed from the name because these style sheets could also be applied to other markup languages besides HTML).

Unlike existing style languages like DSSSL and FOSI, CSS allowed a document's style to be influenced by multiple style sheets. One style sheet could inherit or "cascade" from another, permitting a mixture of stylistic preferences controlled equally by the site designer and user.

Lie's proposal was presented at the "Mosaic and the Web" conference (later called WWW2) in Chicago, Illinois in 1994, and again with Bert Bos in 1995. Around this time the W3C was already being established, and took an interest in the development of CSS. It organized a workshop toward that end chaired by Steven Pemberton. This resulted in W3C adding work on CSS to the deliverables of the HTML editorial review board (ERB). Lie and Bos were the primary technical staff on this aspect of the project, with additional members, including Thomas Reardon of Microsoft, participating as well. In August 1996 Netscape Communication Corporation presented an alternative style sheet language called JavaScript Style Sheets (JSSS). The spec was never finished and is deprecated. By the end of 1996, CSS was ready to become official, and the CSS level 1 Recommendation was published in December.

Development of HTML, CSS, and the DOM had all been taking place in one group, the HTML Editorial Review Board (ERB). Early in 1997, the ERB was split into three working groups: HTML Working group, chaired by Dan Connolly of W3C; DOM Working group, chaired by Lauren Wood of SoftQuad; and CSS Working group, chaired by Chris Lilley of W3C.

The CSS Working Group began tackling issues that had not been addressed with CSS level 1, resulting in the creation of CSS level 2 on November 4, 1997. It was published as a W3C Recommendation on May 12, 1998. CSS level 3, which was started in 1998, is still under development as of 2009.

In 2005 the CSS Working Groups decided to enforce the requirements for standards more strictly. This meant that already published standards like CSS 2.1, CSS 3 Selectors and CSS 3 Text were pulled back from Candidate Recommendation to Working Draft level.

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PHP

PHP Interview Questions and Answers:-

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What's PHP ?
 
The PHP Hypertext Preprocessor is a programming language that allows web developers to create dynamic content that interacts with databases. PHP is basically used for developing web based software applications. 

--------------------------------------------------------------------------------------------------------------------------------

What Is a Session? 
 
A session is a logical object created by the PHP engine to allow you to preserve data across subsequent HTTP requests.

There is only one session object available to your PHP scripts at any time. Data saved to the session by a script can be retrieved by the same script or another script when requested from the same visitor.

Sessions are commonly used to store temporary data to allow multiple PHP pages to offer a complete functional transaction for the same visitor.

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What is meant by PEAR in php?
 
PEAR is the next revolution in PHP. This repository is bringing higher level programming to PHP. PEAR is a framework and distribution system for reusable PHP components. It eases installation by bringing an automated wizard, and packing the strength and experience of PHP users into a nicely organised OOP library. PEAR also provides a command-line interface that can be used to automatically install "packages"

Answer2:
PEAR is short for "PHP Extension and Application Repository" and is pronounced just like the fruit. The purpose of PEAR is to provide:
A structured library of open-sourced code for PHP users
A system for code distribution and package maintenance
A standard style for code written in PHP
The PHP Foundation Classes (PFC),
The PHP Extension Community Library (PECL),
A web site, mailing lists and download mirrors to support the PHP/PEAR community
PEAR is a community-driven project with the PEAR Group as the governing body. The project has been founded by Stig S. Bakken in 1999 and quite a lot of people have joined the project since then.

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How can we know the number of days between two given dates using PHP?
 
Simple arithmetic:

$date1 = date('Y-m-d');
$date2 = '2006-07-01';
$days = (strtotime() - strtotime()) / (60 * 60 * 24);
echo "Number of days since '2006-07-01': $days";

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How can we repair a MySQL table? 

The syntex for repairing a mysql table is:

REPAIR TABLE tablename
REPAIR TABLE tablename QUICK
REPAIR TABLE tablename EXTENDED

This command will repair the table specified.
If QUICK is given, MySQL will do a repair of only the index tree.
If EXTENDED is given, it will create index row by row. 

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What is the difference between $message and $$message?
 
$message is a simple variable whereas $$message is a reference variable. Example:
$user = 'bob'

is equivalent to

$holder = 'user';
$$holder = 'bob';

They are both variables. But $message is a variable with a fixed name. $$message is a variable who's name is stored in $message. For example, if $message contains "var", $$message is the same as $var.

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What Is a Persistent Cookie? 
 
A persistent cookie is a cookie which is stored in a cookie file permanently on the browser's computer. By default, cookies are created as temporary cookies which stored only in the browser's memory. When the browser is closed, temporary cookies will be erased. You should decide when to use temporary cookies and when to use persistent cookies based on their differences:
*Temporary cookies can not be used for tracking long-term information.
*Persistent cookies can be used for tracking long-term information.
*Temporary cookies are safer because no programs other than the browser can access them.
*Persistent cookies are less secure because users can open cookie files see the cookie values.


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What does a special set of tags <?= and ?> do in PHP? 
 
The output is displayed directly to the browser.  

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How do you define a constant?
 
Via define() directive, like define ("MYCONSTANT", 100);

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What are the differences between require and include, include_once? 
 
require_once() and include_once() are both the functions to include and evaluate the specified file only once. If the specified file is included previous to the present call occurrence, it will not be done again.

But require() and include() will do it as many times they are asked to do.

The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. The major difference between include() and require() is that in failure include() produces a warning message whereas require() produces a fatal errors.

All three are used to an include file into the current page.
If the file is not present, require(), calls a fatal error, while in include() does not.
The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. It des not call a fatal error if file not exists. require_once() does the same as include_once(), but it calls a fatal error if file not exists.

File will not be included more than once. If we want to include a file once only and further calling of the file will be ignored then we have to use the PHP function include_once(). This will prevent problems with function redefinitions, variable value reassignments, etc.

--------------------------------------------------------------------------------------------------------------------------------

What is meant by urlencode and urldecode?
 
 urlencode() returns the URL encoded version of the given string. URL coding converts special characters into % signs followed by two hex digits. For example: urlencode("10.00%") will return "10%2E00%25". URL encoded strings are safe to be used as part of URLs.
urldecode() returns the URL decoded version of the given string.

string urlencode(str) - Returns the URL encoded version of the input string. String values to be used in URL query string need to be URL encoded. In the URL encoded version:

Alphanumeric characters are maintained as is.
Space characters are converted to "+" characters.
Other non-alphanumeric characters are converted "%" followed by two hex digits representing the converted character.

string urldecode(str) - Returns the original string of the input URL encoded string.

For example:

$discount ="10.00%";
$url = "http://domain.com/submit.php?disc=".urlencode($discount);
echo $url;

 
you will get "http://domain.com/submit.php?disc=10%2E00%25".

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How To Get the Uploaded File Information in the Receiving Script?

Once the Web server received the uploaded file, it will call the PHP script specified in the form action attribute to process them. This receiving PHP script can get the uploaded file information through the predefined array called $_FILES. Uploaded file information is organized in $_FILES as a two-dimensional array as:
$_FILES[$fieldName]['name'] - The Original file name on the browser system.
$_FILES[$fieldName]['type'] - The file type determined by the browser.
$_FILES[$fieldName]['size'] - The Number of bytes of the file content.
$_FILES[$fieldName]['tmp_name'] - The temporary filename of the file in which the uploaded file was stored on the server.
$_FILES[$fieldName]['error'] - The error code associated with this file upload.

The $fieldName is the name used in the <INPUT TYPE=FILE, NAME=fieldName>.

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What is the difference between mysql_fetch_object and mysql_fetch_array? 
 
MySQL fetch object will collect first single matching record where mysql_fetch_array will collect all matching records from the table in an array

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How can I execute a PHP script using command line? 
 
Just run the PHP CLI (Command Line Interface) program and provide the PHP script file name as the command line argument. For example, "php myScript.php", assuming "php" is the command to invoke the CLI program.
Be aware that if your PHP script was written for the Web CGI interface, it may not execute properly in command line environment. 

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I am trying to assign a variable the value of 0123, but it keeps coming up with a different number, what’s the problem? 
 
PHP Interpreter treats numbers beginning with 0 as octal. Look at the similar PHP interview questions for more numeric problems.

--------------------------------------------------------------------------------------------------------------------------------

What’s PHP ?

The PHP Hypertext Preprocessor is a programming language that allows web developers to create dynamic content that interacts with databases. PHP is basically used for developing web based software applications.What Is a Session?

A session is a logical object created by the PHP engine to allow you to preserve data across subsequent HTTP requests.There is only one session object available to your PHP scripts at any time. Data saved to the session by a script can be retrieved by the same script or another script when requested from the same visitor.Sessions are commonly used to store temporary data to allow multiple PHP pages to offer a complete functional transaction for the same visitor. 

--------------------------------------------------------------------------------------------------------------------------------

What is meant by PEAR in php?

PEAR is the next revolution in PHP. This repository is bringing higher level programming to PHP. PEAR is a framework and distribution system for reusable PHP components. It eases installation by bringing an automated wizard, and packing the strength and experience of PHP users into a nicely organised OOP library. PEAR also provides a command-line interface that can be used to automatically install “packages”

PEAR is short for “PHP Extension and Application Repository” and is pronounced just like the fruit. The purpose of PEAR is to provide:

A structured library of open-sourced code for PHP users

A system for code distribution and package maintenance

A standard style for code written in PHP

The PHP Foundation Classes (PFC),

The PHP Extension Community Library (PECL),

A web site, mailing lists and download mirrors to support the PHP/PEAR community

PEAR is a community-driven project with the PEAR Group as the governing body. The project has been founded by Stig S. Bakken in 1999 and quite a lot of people have joined the project since then. 

--------------------------------------------------------------------------------------------------------------------------------

How can we know the number of days between two given dates using PHP? 

Simple arithmetic:

$date1 = date(‘Y-m-d’);

$date2 = ’2006-07-01′;

$days = (strtotime() – strtotime()) / (60 * 60 * 24);

echo “Number of days since ’2006-07-01′: $days”;

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How can we repair a MySQL table?  

The syntex for repairing a mysql table is:

REPAIR TABLE tablename

REPAIR TABLE tablename QUICK

REPAIR TABLE tablename EXTENDED

This command will repair the table specified.

If QUICK is given, MySQL will do a repair of only the index tree.

If EXTENDED is given, it will create index row by row. 

 --------------------------------------------------------------------------------------------------------------------------------

What is the difference between $message and $$message? 

$message is a simple variable whereas $$message is a reference variable. Example:

$user = ‘bob’

is equivalent to

$holder = ‘user’;

$$holder = ‘bob’;Anwser 2:

They are both variables. But $message is a variable with a fixed name. $$message is a variable who’s name is stored in $message. For example, if $message contains “var”, $$message is the same as $var.

--------------------------------------------------------------------------------------------------------------------------------

What Is a Persistent Cookie?

A persistent cookie is a cookie which is stored in a cookie file permanently on the browser’s computer. By default, cookies are created as temporary cookies which stored only in the browser’s memory. When the browser is closed, temporary cookies will be erased. You should decide when to use temporary cookies and when to use persistent cookies based on their differences:

*Temporary cookies can not be used for tracking long-term information.

*Persistent cookies can be used for tracking long-term information.

*Temporary cookies are safer because no programs other than the browser can access them.

*Persistent cookies are less secure because users can open cookie files see the cookie values.

--------------------------------------------------------------------------------------------------------------------------------

What does a special set of tags <?= and ?> do in PHP?

The output is displayed directly to the browser.How do you define a constant?

Via define() directive, like define (“MYCONSTANT”, 100); 

--------------------------------------------------------------------------------------------------------------------------------

What are the differences between require and include, include_once?

require_once() and include_once() are both the functions to include and evaluate the specified file only once. If the specified file is included previous to the present call occurrence, it will not be done again.But require() and include() will do it as many times they are asked to do.

The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. The major difference between include() and require() is that in failure include() produces a warning message whereas require() produces a fatal errors.

All three are used to an include file into the current page.

If the file is not present, require(), calls a fatal error, while in include() does not.

The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. It des not call a fatal error if file not exists. require_once() does the same as include_once(), but it calls a fatal error if file not exists.

File will not be included more than once. If we want to include a file once only and further calling of the file will be ignored then we have to use the PHP function include_once(). This will prevent problems with function redefinitions, variable value reassignments, etc.

--------------------------------------------------------------------------------------------------------------------------------

What is meant by urlencode and urldecode?

urlencode() returns the URL encoded version of the given string. URL coding converts special characters into % signs followed by two hex digits. For example: urlencode(“10.00%”) will return “10%2E00%25″. URL encoded strings are safe to be used as part of URLs.

urldecode() returns the URL decoded version of the given string.Anwser 2:

string urlencode(str) – Returns the URL encoded version of the input string. String values to be used in URL query string need to be URL encoded. In the URL encoded version:

Alphanumeric characters are maintained as is.

Space characters are converted to “+” characters.

Other non-alphanumeric characters are converted “%” followed by two hex digits representing the converted character.

string urldecode(str) – Returns the original string of the input URL encoded string.For example:

$discount =”10.00%”;

$url = “http://domain.com/submit.php?disc=”.urlencode($discount);

echo $url;You will get “http://domain.com/submit.php?disc=10%2E00%25″.

--------------------------------------------------------------------------------------------------------------------------------

How To Get the Uploaded File Information in the Receiving Script?

Once the Web server received the uploaded file, it will call the PHP script specified in the form action attribute to process them. This receiving PHP script can get the uploaded file information through the predefined array called $_FILES. Uploaded file information is organized in $_FILES as a two-dimensional array as:

$_FILES[$fieldName]['name'] – The Original file name on the browser system.

$_FILES[$fieldName]['type'] – The file type determined by the browser.

$_FILES[$fieldName]['size'] – The Number of bytes of the file content.

$_FILES[$fieldName]['tmp_name'] – The temporary filename of the file in which the uploaded file was stored on the server.

$_FILES[$fieldName]['error'] – The error code associated with this file upload.

The $fieldName is the name used in the <INPUT TYPE=FILE, NAME=fieldName>. 

--------------------------------------------------------------------------------------------------------------------------------

What is the difference between mysql_fetch_object and mysql_fetch_array? 

MySQL fetch object will collect first single matching record where mysql_fetch_array will collect all matching records from the table in an array

--------------------------------------------------------------------------------------------------------------------------------

How can I execute a PHP script using command line? 

Just run the PHP CLI (Command Line Interface) program and provide the PHP script file name as the command line argument. For example, “php myScript.php”, assuming “php” is the command to invoke the CLI program.

Be aware that if your PHP script was written for the Web CGI interface, it may not execute properly in command line environment.I am trying to assign a variable the value of 0123, but it keeps coming up with a different number, what’s the problem?

PHP Interpreter treats numbers beginning with 0 as octal. Look at the similar PHP interview questions for more numeric problems.Would I use print “$a dollars” or “{$a} dollars” to print out the amount of dollars in this example?

In this example it wouldn’t matter, since the variable is all by itself, but if you were to print something like “{$a},000,000 mln dollars”, then you definitely need to use the braces.What are the different tables present in MySQL? Which type of table is generated when we are creating a table in the following syntax: create table employee(eno int(2),ename varchar(10))?

Total 5 types of tables we can create

1. MyISAM2. Heap

3. Merge

4. INNO DB

5. ISAM

MyISAM is the default storage engine as of MySQL 3.23. When you fire the above create query MySQL will create a MyISAM table.

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How To Create a Table? 

If you want to create a table, you can run the CREATE TABLE statement as shown in the following sample script:

<?php

include “mysql_connection.php”;

$sql = “CREATE TABLE Tech_links (“

. ” id INTEGER NOT NULL”

. “, url VARCHAR(80) NOT NULL”

. “, notes VARCHAR(1024)”

. “, counts INTEGER”

. “, time TIMESTAMP DEFAULT sysdate()”

. “)”;

if (mysql_query($sql, $con)) {

print(“Table Tech_links created.\n”);

} else {

print(“Table creation failed.\n”);

}

mysql_close($con);

?>

Remember that mysql_query() returns TRUE/FALSE on CREATE statements. If you run this script, you will get something like this:

Table Tech_links created.

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How can we encrypt the username and password using PHP? 

You can encrypt a password with the following Mysql>SET PASSWORD=PASSWORD(“Password”);

You can use the MySQL PASSWORD() function to encrypt username and password. For example,

INSERT into user (password, …) VALUES (PASSWORD($password”)), …);

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How do you pass a variable by value? 

Just like in C++, put an ampersand in front of it, like $a = &$b

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What is the functionality of the functions STRSTR() and STRISTR()? 

string strstr ( string haystack, string needle ) returns part of haystack string from the first occurrence of needle to the end of haystack. This function is case-sensitive.

stristr() is idential to strstr() except that it is case insensitive.When are you supposed to use endif to end the conditional statement?

When the original if was followed by : and then the code block without braces.How can we send mail using JavaScript?

No. There is no way to send emails directly using JavaScript.

But you can use JavaScript to execute a client side email program send the email using the “mailto” code. Here is an example:

function myfunction(form)

{

tdata=document.myform.tbox1.value;

location=”mailto:mailid@domain.com?subject=…”;

return true;

 }

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What is the functionality of the function strstr and stristr? 

strstr() returns part of a given string from the first occurrence of a given substring to the end of the string. For example: strstr(“user@example.com”,”@”) will return “@example.com”.

stristr() is idential to strstr() except that it is case insensitive.What is the difference between ereg_replace() and eregi_replace()?

eregi_replace() function is identical to ereg_replace() except that it ignores case distinction when matching alphabetic characters.

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How do I find out the number of parameters passed into function9. ? 

func_num_args() function returns the number of parameters passed in.What is the purpose of the following files having extensions: frm, myd, and myi? What these files contain?

In MySQL, the default table type is MyISAM.

Each MyISAM table is stored on disk in three files. The files have names that begin with the table name and have an extension to indicate the file type.

The ‘.frm’ file stores the table definition.

The data file has a ‘.MYD’ (MYData) extension.

The index file has a ‘.MYI’ (MYIndex) extension, 

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If the variable $a is equal to 5 and variable $b is equal to character a, what’s the value of $$b?

100, it’s a reference to existing variable.

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How To Protect Special Characters in Query String?

If you want to include special characters like spaces in the query string, you need to protect them by applying the urlencode() translation function. The script below shows how to use urlencode():

<?php

print(“<html>”);

print(“<p>Please click the links below”

.” to submit comments about TECHPreparation.com:</p>”);

$comment = ‘I want to say: “It\’s a good site! :->”‘;

$comment = urlencode($comment);

print(“<p>”

.”<a href=\”processing_forms.php?name=Guest&comment=$comment\”>”

.”It’s an excellent site!</a></p>”);

$comment = ‘This visitor said: “It\’s an average site! “‘;

$comment = urlencode($comment);

print(“<p>”

.’<a href=”processing_forms.php?’.$comment.’”>’

.”It’s an average site.</a></p>”);

print(“</html>”);

?>

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Are objects passed by value or by reference?

Everything is passed by value. 

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What are the differences between DROP a table and TRUNCATE a table? 

 DROP TABLE table_name – This will delete the table and its data.

TRUNCATE TABLE table_name – This will delete the data of the table, but not the table definition. 

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How do you call a constructor for a parent class?

parent::constructor($value)

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WHAT ARE THE DIFFERENT TYPES OF ERRORS IN PHP?

Here are three basic types of runtime errors in PHP:

1. Notices: These are trivial, non-critical errors that PHP encounters while executing a script – for example, accessing a variable that has not yet been defined. By default, such errors are not displayed to the user at all – although you can change this default behavior.

2. Warnings: These are more serious errors – for example, attempting to include() a file which does not exist. By default, these errors are displayed to the user, but they do not result in script termination.

3. Fatal errors: These are critical errors – for example, instantiating an object of a non-existent class, or calling a non-existent function. These errors cause the immediate termination of the script, and PHP’s default behavior is to display them to the user when they take place.

Internally, these variations are represented by twelve different error types

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What’s the special meaning of __sleep and __wakeup? 

__sleep returns the array of all the variables than need to be saved, while __wakeup retrieves them.

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How can we submit a form without a submit button? 

If you don’t want to use the Submit button to submit a form, you can use normal hyper links to submit a form. But you need to use some JavaScript code in the URL of the link. For example:

<a href=”javascript: document.myform.submit();”>Submit Me</a> Why doesn’t the following code print the newline properly? <?php $str = ‘Hello, there.\nHow are you?\nThanks for visiting techpreparation’; print $str; ?>

Because inside the single quotes the \n character is not interpreted as newline, just as a sequence of two characters – \ and n.

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Would you initialize your strings with single quotes or double quotes? 

Since the data inside the single-quoted string is not parsed for variable substitution, it’s always a better idea speed-wise to initialize a string with single quotes, unless you specifically need variable substitution.How can we extract string ‘abc.com ‘ from a string http://info@abc.com using regular expression of php?

We can use the preg_match() function with “/.*@(.*)$/” as

the regular expression pattern. For example:

preg_match(“/.*@(.*)$/”,”http://info@abc.com”,$data);

Ex: Assume we are logging in with username and password.

GET: we are submitting a form to login.php, when we do submit or similar action, values are sent through visible query string (notice ./login.php?username=…&password=… as URL when executi>

When we submit a form, which has the GET method it displays pair of name/value used in the form at the address bar of the browser preceded by url. Post method doesn’t display these values.

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What is the difference between the functions unlink and unset? 

unlink() is a function for file system handling. It will simply delete the file in context.

unset() is a function for variable management. It will make a variable undefined. 

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How come the code works, but doesn’t for two-dimensional array of mine? 

Any time you have an array with more than one dimension, complex parsing syntax is required. print “Contents: {$arr[1][2]}” would’ve worked.How can we register the variables into a session?

session_register($session_var);

$_SESSION['var'] = ‘value’;

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What are the different functions in sorting an array?

Sorting functions in PHP:

asort()

arsort()

ksort()krsort()

uksort()

sort()

natsort()

rsort()

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How can we know the count/number of elements of an array? 

2 ways:

a) sizeof($array) – This function is an alias of count()

b) count($urarray) – This function returns the number of elements in an array.

Interestingly if you just pass a simple var instead of an array, count() will return 1.

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How many ways we can pass the variable through the navigation between the pages? 

At least 3 ways:

1. Put the variable into session in the first page, and get it back from session in the next page.

2. Put the variable into cookie in the first page, and get it back from the cookie in the next page.

3. Put the variable into a hidden form field, and get it back from the form in the next page.What is the maximum length of a table name, a database name, or a field name in MySQL?

Database name: 64 characters

Table name: 64 characters

Column name: 64 characters

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How many ways we can we find the current date using MySQL?

SELECT CURDATE();

SELECT CURRENT_DATE();

SELECT CURTIME();

SELECT CURRENT_TIME();

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Give the syntax of GRANT commands? 

The generic syntax for GRANT is as following

GRANT [rights] on [database] TO [username@hostname] IDENTIFIED BY [password]

Now rights can be:

a) ALL privilages

b) Combination of CREATE, DROP, SELECT, INSERT, UPDATE and DELETE etc.

We can grant rights on all databse by usingh *.* or some specific database by database.* or a specific table by database.table_name.Give the syntax of REVOKE commands?

The generic syntax for revoke is as following

REVOKE [rights] on [database] FROM [username@hostname]

Now rights can be:

a) ALL privileges

b) Combination of CREATE, DROP, SELECT, INSERT, UPDATE and DELETE etc.We can grant rights on all database by using *.* or some specific database by database.* or a specific table by database.table_name. 

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What is the difference between CHAR and VARCHAR data types? 

CHAR is a fixed length data type. CHAR(n) will take n characters of storage even if you enter less than n characters to that column. For example, “Hello!” will be stored as “Hello! ” in CHAR(10) column.

VARCHAR is a variable length data type. VARCHAR(n) will take only the required storage for the actual number of characters entered to that column. For example, “Hello!” will be stored as “Hello!” in VARCHAR(10) column.

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